Plastic ski track



May 13, 1969 F. F. DEL PIANO ET Al 3,443,493

PLASTIC SKI TRACK Filed May 2, 1968 sh ei of 4 I H! l! WW! WI!!! INVENTORS Fran c/s Freden'c 09/ Piano,

Tina Cazzan/ga ByDaw's, Hex/; 1%17/7/0 8 Hopgoad Attorneys May 13, 1969 F. F. DEL. PIANO ET AL 3, 4

PLASTIC SKI 'TRACK iled May 2, 1 968 7 Sheet i of 4 INVENTORS Franc/s Frederic 08/ Pig/2a 7700 Cazzan/ga ByDawLg hbx/gf'a/mfullaflapgoad Aftomeys y 1969 F. F. DEL PIANO ET AL 3,443,493

PLASTI C S K I T R A CK Filed May 2, i968 shet 3 of 4 6 0 /6' w H64 p 'I f g i I y i 5 i l 5 I i! s v i 5: I /5 /5 INVENT R 0 5 Francis Freda/t 06/ Piano 7/00 Cazzom'ga By Dav/s, Hax/k, Faithful/8Hapgo0d Attorneys May 13,1969 EL mNoj TAL 3,443,493

PLASTIC SKI TRACK Sheet Filed May 2, 1968 INVENTORIS Franc/s Freder/c Del P/ano T/no Cozzan/ga By flaw'gHoxligFaif/rfulla Hapgooa' Alrorneys United States Patent 3,443,493 PLASTIC SKI TRACK Francis F. Del Piano, 32 E. 68th St., New York, NY. 10021, and Tino Cazzaniga, Via Zavattari 1, Monza,

Italy Filed May 2, 1968, Ser. No. 726,137 Int. Cl. E041. 15/00; A63g 21/02 US. Cl. 943 12 Claims ABSTRACT OF THE DISCLOSURE The present invention relates to a plastic ski track suitable for all-weather skiing, for location on soil, grass or other sloping surface. The track is composed of interlocking elements having two tangentially joined, roughly round portions with a number of concentric rows of upright bristles. Preferably, the interlocking elements are made by injection molding of a polyethylene-based composition, described more particularly hereafter. The track elements may be readily assembled by interlocking to cover the entire skiing surface of any desired area. Each of the preferred elements covers about one-half square food of surface.

It is an objective of this invention to provide interlocking ski track elements, readily fabricated by injection molding of a plastic composition, which may be locked together to form a ski track on a surface of any desired area, and which in place will simulate a snow surface for skiing.

The invention will be clearly understood by reference to the attached drawings, illustrating the preferred embodiment of the track elements, wherein:

FIGURE 1 is a top plan view of one of the interlocking track elements with only a portion of the upright bristles being shown;

FIGURE 2 is a cross-sectional view of the track element, taken along the plane 2-2 of FIGURE 1;

FIGURE 3 is a bottom plan view of the track element of FIGURE 1;

FIGURE 4 is an enlarged, cross-sectional view of a portion of the track element showing one of each of the seven concentric rows of bristles, and their relative heights, taken along plane 4-4 of FIGURE 1;

FIGURE 5 is a cross-sectional view of the interlocking portions of two joined track elements; and

FIGURE 6 is a perspective view of a number of interlocked elements forming a portion of a track.

With reference to FIGURES 1-3, it can be seen that the interlocking element is composed of two roughly round portions 10 and 11, joined tangentially at bridge 12.

The particular shape of the roughly round portions is not critical, although the circular shape shown is preferred. Thus the portions may be oblong, elliptical or polygonal as well. The term roughly round is intended to include such similar shapes.

The element has three studs 13 and three grooves 14 for interlocking with adjacent elements (FIGS. 1 and 3). An interlocked study and groove combination is shown in FIGURE 5. The particular means of interlocking is ice not critical, but the illustrated means is preferred, for the elements are thereby readily locked together by downward pressure on stud 13. The interlocked elements form a virtually solid flat track surface.

Each portion has an annual flat surface 15 and therewithin an opening 16. As shown in FIGURES 1, 2 and 4, the annular flat surface 15 may be depressed somewhat. The annular surface 15 supports a large number of upright bristles 17, in concentric rows. As shown in FIGURE 2 and best in FIGURE 4, the rows of bristles 17 are of progressively varying height such that the radially innermost and outermost rows are relatively short and the intermediate rows are relatively tall. Thus, with reference to FIGURE 4, the bristles 17 are in seven concentric rows a-g, lettering radially outwardly, and rows a and g are short, rows 0, d and e are tall, and rows b and f are of intermediate height. This shape will be called here a bell-shaped profile-that is, the profile defined by the upper ends of the bristles viewed in radial, elevated section, as in FIGURE 4. This bell-shaped profile of the concentric rows of upright bristles allows at once both very fast skiing in straight course and good holding without excessive slipping on slalom or turning courses.

The bristles are tough and coarse, and quite rigid to vertical force, but tend to deflect sideways under pressure from skis. The taller, intermediate rows of bristles absorb the pressure initially, and, upon their deflection the shorter rows progressively absorb more and more of the pressure. It will be apparent that the tallest rows of bristles absorb the most pressure and undergo the greatest deflection, and it is preferred that the shortest rows absorb little or no deflection during skiing in straight course, while the rows of intermediate height undergo intermediate deflection. Preferably also, as shown in FIGURE 4, the bristles are slightly tapered from bottom to top.

The underside of the track elements is largely open, and has a network of vertical ribs for support of the track element. The network of vertical ribs permits the track elements, while being lightweight, to be readily anchored to a supporting surface, to maintain the annular flat surface and bristles of the elements at the desired angle and elevation. As shown best in FIGURES 2 and 3, the vertical ribs comprise an outer peripheral rib 18, two annular ribs 19, eight radial ribs 20 and four bridging ribs 21. These ribs in combination provide both elevated support for the fiat surface and upright bristles, and anchoring means for the track elements on ground or similar surfaces, such as grass or snow. Installation on grass is particularly suitable, for the growth of grass will serve even more to anchor the track to the ground. Further, the grass may be cut at regular intervals, with the exercise of due care, of course, to avoid cutting the track bristles. It will be appreciated that the particular location and number of support ribs is not critical, but that shown is generally symmetrical and preferred.

The ski track is fabricated by locking the individual track elements together in two dimensions, as shown partially in FIGURE 6, over the supporting surface or ground. The ski surface, that is, the bristles, assume the same contour as the supporting surface. The track when installed may be permanent, for use for many seasons, both summer and winter. If individual elements become damaged, they may be readily replaced without disclocation of the track.

The track elements may be fabricated by injection molding of any suitable plastic material, such as the preferred polyethylene-based plastic described fully below, such molding techniques being within the skill of the art. The actual dimensions of the elements are not critical, but the approximate, preferred dimensions are given below.

3 Element, overall: Inches Length 13%. Width 6 /2 Height 1V2 Flat annular surface:

Inner diameter 4 Outer diameter 6 /2 Bristles:

Minimum height Maximum height 1% Diameter The composition of the plastic used to fabricate the track elements is important in order to obtain the desired effects. Thus the composition must provide suflicient compressive strength and attrition resistance for the bristles, supporting surface and ribs to withstand continued use in a ski track. Further, the surface of the track elements must be sufficiently inert to atmospheric conditions to obtain a substantial life of service. Also, it is important that the composition be sufficiently self-lubricating to permit unhindered skiing and to avoid damage to the skis. Further, the composition must provide suflicient flexibility and resilience to the bristles, to allow fast straight skiing and turning without excessive slippage. It will be appreciated that the ideal composition or compositions will at least in part depend on the dimensions of the elements, in that the two factors are somewhat interrelated.

The composition, having the desired properties, may

be comprised-in part, predominantly or substantially completely-of any of the several tough, flexible plastic materials, including polyolefins such as polyethylene, polypropylene, polybutenes, polyisobutylene; halogenated olefin polymers such as polytetrafluoroethylene or polyvinyl chloride; polystyrene; synthetic rubbers such as polybutadiene, styrene-butadiene rubber, neoprenes, butyl rubber, polyisoprene and ethylene-propylene rubber; and the like. Preferably, the composition comprises at least a major proportion of a polyolefinpolyethylene or polypropylene, preferably-compounded with others of the tough, flexible plastics referred to above. The preferred component is polyethylene, and the preferred compositions contain at least about 90 percent polyethylene, such compositions hare being called polyethylene-based." The various components of the composition may be combined in any convenient method, including blending and copolymerization. Other components, such as lubricants, antioxidants, stabilizers and the like, may also be added to the composition, as desired. Preferably, an antioxidant and a lubricant are employed.

One composition found particularly suitable for use in fabricating the present track elements is the following:

Component Parts by weight Percent Linear high density polyethylene 95 .000 92 .0 Polyisobutylene (Esso) 7 .500 7 .3 Tinuvin 326 (Geigy)... 0.180 .17 Cyasorb UV531 2 (Nimc 0.361 .35 Irganox 565 3 (Geiay) 0.090 .09 Armid 4 (Italcolloid) 0 .040 .04

1 A trademark of Geigy Chemical Corp., for substituted hydroxyphenyl benzotriazoles, used as ultraviolet absorbers.

2 Apparently a trademark for an ultraviolet absorber.

3 A trademark of Geigy Chemical Corp, for complex high-molecularweiglit stabilizers, used to inhibit oxidation and thermal degradation.

4 A trademark of Armour Industrial Chemical Co. for high-melting amides derived from fatty acids, used here as a lubricant.

It will be evident that the interlocking elements of this invention, the shape and composition of which are above described in full, may be readily locked together to form a unique track surface ideal for all types of skiing under any conditions of weather. The track is light and inexpensive, and may be readily installed in any location, on all surfaces, such as snow, ground or grass. The track may be used even indoors.

We claim:

1. An interlocking track element for use in a ski track comprising an annular flat surface and a plurality of concentric rows of upright bristles extending from said surface, and having means for interlocking said element with a plurality of adjacent elements.

2. The interlocking track element of claim 1, wherein the concentric rows of upright bristles in elevated radial section define a bell-shaped profile.

3. The interlocking track element of claim 1, wherein the element is composed of a polyethylene-based composition.

4. An interlocking track element, for combination with other elements to form a ski track, which comprises: two roughly round portions connected bp a bridge, said portions each having an annular flat surface and an opening therewithin; a large number of upright bristles in concentric rows, extending from said annular flat surface, said concentric rows of upright bristles in elevated radial section defining a bell-shaped profile; means for interlocking said element with adjacent elements; and a largely open underside having a network of vertical ribs for support.

5. The interlocking track element of claim 4, wherein each roughly round portion is circular, and wherein the circular, concentric rows of upright bristles of each portion number about seven, the radially innermost and outermost rows of which being relatively short and the intermediate rows being relatively tall.

6. The interlocking track element of claim 4, wherein the upright bristles are between about A and 1% inches tall.

7. The interlocking track element of claim 4, wherein each annular fiat surface is between about 4 and 6 /2 inches in diameter.

8. The interlocking track element of claim 4, wherein the network of vertical ribs comprises a peripheral rib, two annular ribs and a number of radial ribs.

9. The interlocking track element of claim 4, wherein the element is fabricated by injection molding of a plastic material, selected from the group consisting of polyolefins, halogenated olefin polymers, polystyrene synthetic rubbers, and combinations thereof.

10. The interlocking track element of claim 9, wherein the plastic material is polyethylene-based.

11. The interlocking track element of claim 9, wherein the plastic material contains a lubricant and an antioxidant.

12. The interlocking track element of claim 4, wherein the element is fabricated by injection molding of a plastic material comprising about -95 percent high density polyethylene, about 5-10 percent polyisobutylene, about 0.251 percent of a lubricant and about 0.25l percent of an antioxidant, ultraviolet absorber or other stabilizer.

References Cited UNITED STATES PATENTS 3,047,292 7/1962 Acquaderni 272-565 3,233,893 2/1966 Meyer 272-56.5 3,251,596 5/1966 Nilzaki 27256.5 3,350,092 10/1967 Maki 272-565 JACOB L. NACKENOFF, Primary Examiner.

US. Cl. X.R. 

